Difluorocyclohexyl derivatives as IL-17 modulators

A compound of formula (IIA) or an N-oxide thereof, or a pharmaceutically acceptable salt thereof:

• wherein
• A represents C—R1 or N;
• E represents C—R2 or N;
• R1 represents hydrogen or fluoro;
• R2 represents hydrogen or fluoro;
• R3 represents —NR3aR3b;
• or R3 represents a group of formula (Wa):
• in which the asterisk (*) represents the point of attachment to the remainder of the molecule;
• W represents the residue of an optionally substituted saturated monocyclic ring containing 3 to 6 carbon atoms, one nitrogen atom, and 0, 1, 2 or 3 additional heteroatoms independently selected from N, O and S, but containing no more than one O or S atom;
• or
• W represents the residue of an optionally substituted saturated bicyclic ring system containing 4 to 10 carbon atoms, one nitrogen atom, and 0, 1, 2 or 3 additional heteroatoms independently selected from N, O and S, but containing no more than one O or S atom;
• or
• W represents the residue of an optionally substituted saturated spirocyclic ring system containing 5 to 10 carbon atoms, one nitrogen atom, and 0, 1, 2 or 3 additional heteroatoms independently selected from N, O and S, but containing no more than one O or S atom;
• R3a represents hydrogen or C1-6 alkyl;
• R3b represents C1-6 alkyl, C3-7 cycloalkyl, C3-7 cycloalkyl(C1-6)alkyl, aryl, aryl(C1-6)alkyl, C3-7 heterocycloalkyl, C3-7 heterocycloalkyl(C1-6)alkyl, heteroaryl or heteroaryl(C1-6)alkyl, any of which groups may be optionally substituted by one or more substituents;
• R4a represents hydrogen, fluoro or hydroxy;
• or R4a represents C1-6 alkyl, which group may be optionally substituted by one or more substituents;
• and
• R4b represents hydrogen, fluoro or C1-6 alkyl;
• or
• R4a and R4b, when taken together with the carbon atom to which they are both attached, represent C3-9 cycloalkyl or C3-7 heterocycloalkyl, either of which groups may be optionally substituted by one or more substituents;
• and
• R16 represents methyl, ethyl, isopropyl or cyclopropyl.